1. Field of the Invention
The present invention relates to an optical disc apparatus and an optical power control method, and relates particularly to a technique for controlling optical power, which suppresses an influence of a phenomenon that an output of a power detection portion that detects optical power varies with a change in environmental temperature.
2. Description of Related Art
Conventionally, an optical disk apparatus has been used to reproduce information recorded on an optical disc and/or to record information on an optical disk. In such an optical disc apparatus, in order to achieve stable quality in reproduction and/or recording, generally, reproduction and/or recording with respect to an optical disk are performed while optical power of light being used to irradiate the optical disk is controlled.
That is, an optical disk apparatus is provided with a power detection portion (front monitor detector (FMD)) that detects optical power of light emitted from a light source. In the optical disk apparatus, reproduction and/or recording with respect to an optical disc are performed while feedback control (APC (auto power control)) is performed so that optical power (intensity) of light detected by the power detection portion attains a predetermined value.
JP-A-2008-117488 discloses a technique for performing APC in which a correction in consideration of temperature characteristics of an optical component and an electronic component is made so that irradiation power can be controlled with high accuracy. It is disclosed therein that, in order to correct a variation in detection sensitivity of an FMD with a temperature change, a sensitivity coefficient of the FMD is changed depending on a temperature change, and based on a result of detection by the FMD, a target power value of an APC circuit is calculated.